1. Field of the Invention
The present invention relates to an iron-type golf club head having improved directional stability of a hit golf ball.
2. Description of the Background Art
In recent years, an iron-type golf club head a position of whose center of gravity was improved by bonding more than two kinds of different metallic materials has been proposed. FIG. 10 shows one example of such an iron-type gold club head a. The club head a includes a main portion b, and weight members ct, ch having heavier specific gravity than the main portion b, the weight members ct, ch being respectively arranged in a lower part of a toe portion t and a heel portion h on a rear of a face portion of the main portion b. In this type of club head a, great mass is allocated to a toe side and a heel side of a face portion. Hence, a moment of inertia around a vertical axis passing through the center of gravity of the head G (which may be hereinafter referred to as the “moment of inertia Ig”) increases, and orientation of a face does not easily change even when a golf ball is hit on the toe side or the heel side of a sweet spot of the face, thus improving the directional stability of the hit golf ball.
However, the gold club head mentioned above tends to have a greater moment of inertia around an axial centerline CL of a shaft (which may be hereinafter referred to as the “moment of inertia Ic”). Such a golf club head a having the great moment of inertia Ic originally had a problem that when a golfer swung it, the face did not fully return to the position at address, thus causing him/her to easily make a slice shot. There are related technologies as shown below:    [Patent Document 1] Japanese Patent Application Publication No. 2010-29380,    [Patent Document 2] Japanese Patent Application Publication No. 2009-291488.